Perspectives of coronary excimer laser angioplasty: Multiplexing, saline flushing, and acoustic ablation control
✍ Scribed by Haase, Karl K.; Rose, Carsten; Duda, Stephan; Baumbach, Andreas; Oberhoff, Martin; Anthanasiadis, Anastasios; Karsch, Karl R.
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 134 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0196-8092
No coin nor oath required. For personal study only.
✦ Synopsis
Background and
Objective: Bubble formation, pressure wave generation, and cavitations constitute major factors influencing the outcome of clinical Excimer laser angioplasty. Thus, the rationale of this study was to determine the extent of pressure waves occurring during excimer laser ablation and to discuss possibilities that allow a less traumatic plaque removal in the coronary circulation. Study Design/Materials and Methods: Conventional and experimental Xenon-Chlorid-Excimer lasers emitting light at a wavelength of 308nm and a pulse duration of 115ns were used for testing of signals. Whereas the conventional excimer laser light source transmits light through all fibres of a 1.7 mm laser catheter simultaneously, the prototype excimer laser divides the laser beam into several areas of uniform energy fluence by scanning the beam from one section to the other using the intermission between two laser discharges. Hydrophones consisting of piezoelectric films detected the acoustic signals, which were obtained on normal arterial wall and atherosclerotic plaque. Results: Multiplexing decreases maximum pressures for both normal arterial wall and calcified plaque significantly, whereas pressure rise time remains comparable. During ablation of pure blood, a linear increase of peak pressures of 1 MPa at 10 mJ/mm 2 to 7.5 MPa at 50 mJ/mm 2 is found. Contrast media intensifies the extent of pressure wave formation. At 20 mJ/mm 2 , 60% contrast media added to blood results in an increase of maximum pressures from 1.5 MPa up to 5 MPa. Dilution with saline solution is effective; however, high concentrations of > 90% are required to achieve a significant pressure wave reduction. Conclusion: Peak pressures of several thousand kPa occur during excimer laser ablation of contrast media, blood, calcified plaque, and normal arterial wall in a decreasing order. Multiplexing and saline flushing are capable of reducing the intensity of the generated acoustic signals during tissue ablation. It has to